Whilst moving into my new building, I also expanded the shop's
capability to deal with heavier and larger countertops.... and I have
added Quartz to my repertoire. I only install the stuff, and a
fabulous supplier/fabricator gives me exactly what I order. I e-mail
him very precise .dwg drawings. (Back left corner is 89.3 degrees,
that's what I get.) I am looking at buying a proper digitising
template system.

But the stuff is some heavy... 20 pounds per square foot.
Having chatted with a few old hands at the installation game, in
quartz and granite, I learned that there are a lot of material
handling toys around which reduce breakage of countertops and hired
help.

I thought that a lot of Wreckers here could be inspired to make some
of these carts and tables themselves.
Morris Dovey, some time ago, posted links to a cart he had built, and
a friend of mine is very happy with the results.
A few dollies are hardly worth copying, they're cheap enough. (The
shipping might kill that idea though, unless you're lucky enough to
live close to a distributor.)

The people I have dealt with have been very helpful:

https://ecom.granquartz.com/VIA9/index.jsp

That's their online store, just click on the Materials Handling
button, and steal some good ideas.